Review of Methods of Removal of Heavy Metals from Wastewater

Heavy metals like copper, cadmium, chromium, nickel, zinc, lead, arsenic, and mercury are most common pollutants of water owing to their poisonous, persistent nature and non-biodegradable. The expansion of industry is the greatest source of heavy metals. These pollutants spread in different sections of the environment including air, water, soil, fish, vegetables. Human may easily absorb these metals from food and water, because they are very soluble in aquatic media. Different techniques have been developed and applied for wastewater treatment to remove heavy metals from the surrounding environment. These methods include membrane filtration, ion-exchange, adsorption, chemical precipitation, nanotechnology treatments, electrochemical and advanced oxidation processes. In this review, some of the methods are discussed. The different types of water treatment methods were mentioned and surveyed. In addition, the hazardous effect of different metals were mentioned. Advantages and disadvantages of the methods were discussed. Conclusions of the survey were added. Many important references were summarized.